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View Full Version : CTR pistons into B18C7 ITR engine



euGeR
27-04-2004, 11:18 PM
This seems like an interesting mod, for the price.

1. Is it true that CTR pistons will give more compression over JDM ITR pistons in a B18C7?

2. If Pistons + rings were purchased, what is the process of getting them installed? a straight exchange or is there any other type of work required?

3. If compression was raised, is aftermarket EMS absolutely necessary? or can Stock computer re-adjust?

4. What would be the speculative bump in compression/gain/ change in torque curve?

(assuming standard ITR cams)

:idea:

Jim80y
28-04-2004, 01:38 AM
I've been reading about this too, but apparently if using these with fairly agressive cams there could be piston/valve clearance issues because of the domed top of the piston. Compression with these on a stock B18C7 is somewhere around 12.2-12.5:1 .

euGeR
28-04-2004, 07:05 AM
ahhaha yeah I saw your interest in the FS section :)
So on stock CAMS should be no probs, but if using anything above a SPEC B - issues.

Wouldn't be much to gain on stock CAMS would there....

Jim80y
28-04-2004, 09:44 AM
Not too sure to tell you the truth. Could be some sort of gain but would be most beneficial with some sort of aftermarket programmable engine management.

Keep your mits off the CTR pistons :p

j/k

type one
28-04-2004, 11:06 AM
CTR pistons for $550... i think you could get a set of spoon balanced jdm pistons for less.... :) if that's all your after...

Weq
28-04-2004, 12:12 PM
If u are after a set of pistons and going to the trouble of installing them, defaintly get something stronger and forged. It wont cost u much more, and support more power. Oh yeah, while ur at it, new rods wont go atray :)

crx2gen
28-04-2004, 12:50 PM
Yeah. At the end of the day they are 'just' (and I say that with some caution :D ) standard pistons.

wynode
28-04-2004, 12:51 PM
I'm not sure about getting forgies on an NA setup. There are some bad points about getting forgies Weq ;)

McChook
28-04-2004, 07:13 PM
I'm not sure about getting forgies on an NA setup. There are some bad points about getting forgies Weq ;)

Please elaborate

wynode
28-04-2004, 09:37 PM
I'm not sure about getting forgies on an NA setup. There are some bad points about getting forgies Weq ;)

Please elaborateElsewhere........make a thread and i'll reply.

euGeR
28-04-2004, 09:56 PM
I'm not sure about getting forgies on an NA setup. There are some bad points about getting forgies Weq ;)

I don't mind :) I'd like to know to.

As far as I know, ITR/CTR/toda pistons are forged - providing better strengths for High RPM/compression applications, but then, I am only a hobbyist not an engine builder, so feel free to comment.

wynode
28-04-2004, 11:28 PM
Ohh........I didn't know they were forged.....my bad.

But the comment was in relation to Forged pistons requiring to be warmed up, using a bit more oil when cold and also being a bit noisy because of the large piston to bore clearance when cold.

Weq
29-04-2004, 12:41 AM
true that wynny, a small price to pay though.

poid
29-04-2004, 09:14 AM
wyn: that depends also on the construction of the pistons. There are high and low silicon forgies available, now i cant remember which way around it is but one of them has a little less strength and tighter tolerances to reduce piston slap when cold (and hence wear on the cylinder walls) and the other is higher strength with larger clearances needed.

fueltank
29-04-2004, 09:25 AM
wyn: that depends also on the construction of the pistons. There are high and low silicon forgies available, now i cant remember which way around it is but one of them has a little less strength and tighter tolerances to reduce piston slap when cold (and hence wear on the cylinder walls) and the other is higher strength with larger clearances needed.what poid said!

Dvius_Honda
02-05-2004, 11:53 PM
putting CTR pistons in a ITR is not worth the money or hassle... the ITR already has reasonably high compression.

replacing pistons is a pretty big job... and your money could definitely be wiser spent elsewhere - to get better gains for bucks.

tanghy
04-05-2004, 04:20 PM
This seems like an interesting mod, for the price.

1. Is it true that CTR pistons will give more compression over JDM ITR pistons in a B18C7?

2. If Pistons + rings were purchased, what is the process of getting them installed? a straight exchange or is there any other type of work required?

3. If compression was raised, is aftermarket EMS absolutely necessary? or can Stock computer re-adjust?

4. What would be the speculative bump in compression/gain/ change in torque curve?

(assuming standard ITR cams)

:idea:
1 yes there is higher compression

2 you shoudl get the .25 oversized ones, and have your existing sleeeves bored out

3 yes ems needed

tanghy
04-05-2004, 04:27 PM
and to answer a few more questions:

if u use ctr pistons, you can use standard rods
if you use aft mkt pistons, need new rods or need to mod stock rods

and with regards to cost vs "hassle" this is a very cheap way to gain compression

tanghy
04-05-2004, 04:29 PM
also one other thing, big cams like compression, which cannot be achieved by simply chucking in a 2 ply gasket

TODA AU
04-05-2004, 06:26 PM
I'm not sure about getting forgies on an NA setup. There are some bad points about getting forgies Weq ;)

I don't mind :) I'd like to know to.

As far as I know, ITR/CTR/toda pistons are forged - providing better strengths for High RPM/compression applications, but then, I am only a hobbyist not an engine builder, so feel free to comment.

OEM ITR & CTR pistons are not forged, rather a high pressure cast.
SPOON pistons are the same as above...
A balanced set from Spoon is achieved by their weighing new OEM pistons untill they get a matching set... Nothing more...
TODA, JUN, JE, Arias & various others are forged pistons.
They are stronger & can handle higher rpm.
The down sides hinted at by Win include piston slap, noisy running & short life...
These are charateristics common to many if not all of the cheaper forged pistons available...
Top shelf forged pistons use the same piston to bore clearence as OEM pistons...
There are no down sides to using them appart from the expense...
Asuming your engine builder is competant, you do get what you paid for...

Regarding using CTR pistons in a B18C7...
Using a stock head gasket...
The C/R with no other changes will be in the 12.2:1 range...
Maximum rpm should be limited to 9000rpm...

euGeR
06-05-2004, 10:10 PM
Thanks Adrian, Tanghy!

We'll it's starting to look like a good & interesting mod to me.

What could happen if I tried to push 9500RPM ? (assuming spec B's)
What would be the estimated hours of laboured required?

Any other things you can do while the pistons are out?

tofu R
06-05-2004, 11:10 PM
hmm i dont think anyone has mentioned it
but ive seen a car in sydney getting ctr pistons put in ..

the mech that was working on it .. said that you would also require a port 'n' polish
for good measure.

TODA AU
07-05-2004, 07:26 AM
Thanks Adrian, Tanghy!

We'll it's starting to look like a good & interesting mod to me.

What could happen if I tried to push 9500RPM ? (assuming spec B's)
What would be the estimated hours of laboured required?

Any other things you can do while the pistons are out?

Spec B's... LOL, it doesn't matter if you've got whatever cams in..
The cams etc are totally unrelated to this topic...
Just because the engine may want to rev, doesn't mean it should...
The top of the piston will fall off at sustained high rpm... (Over 9000)

Regarding porting the head on an engine only using CTR pistons...
LOL...
Why bother...
It's only ever going to be a half arsed attempt anyway...
The owner clearly is running to a tight budget... (How will he then affort a good port job ? ;) )
& If the engine is being build to a racing regulation that stipulates using an OEM piston... Chances are porting is banned....